// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/base/touch/touch_enabled.h"

#include "base/command_line.h"
#include "base/logging.h"
#include "ui/base/touch/touch_device.h"
#include "ui/base/ui_base_switches.h"
#include "ui/events/base_event_utils.h"
#include "ui/events/event_switches.h"

namespace ui {

namespace {

    enum class TouchEventsStatus {
        AUTO,
        DISABLED,
        ENABLED,
    };

    TouchEventsStatus ComputeTouchFlagStatus()
    {
        auto* command_line = base::CommandLine::ForCurrentProcess();
        const std::string touch_enabled_switch = command_line->HasSwitch(switches::kTouchEvents) ? command_line->GetSwitchValueASCII(switches::kTouchEvents) : switches::kTouchEventsAuto;

        if (touch_enabled_switch.empty() || touch_enabled_switch == switches::kTouchEventsEnabled) {
            return TouchEventsStatus::ENABLED;
        }

        if (touch_enabled_switch == switches::kTouchEventsAuto)
            return TouchEventsStatus::AUTO;

        DLOG_IF(ERROR, touch_enabled_switch != switches::kTouchEventsDisabled) << "Invalid --touch-events option: " << touch_enabled_switch;
        return TouchEventsStatus::DISABLED;
    }

} // namespace

bool AreTouchEventsEnabled()
{
    static TouchEventsStatus touch_flag_status = ComputeTouchFlagStatus();

    // The #touch-events flag is used to force and simulate the presence or
    // absence of touch devices. Only if the flag is set to AUTO, we need to check
    // for the actual availability of touch devices.
    if (touch_flag_status == TouchEventsStatus::AUTO)
        return GetTouchScreensAvailability() == TouchScreensAvailability::ENABLED;

    return touch_flag_status == TouchEventsStatus::ENABLED;
}

} // namespace ui
